Img2Img is broken

Using auto1111 backend. Img2Img works in auto1111.

On fresh install of both auto1111 and this plugin.

payload's `init_images` is `[None]`.

Full stacktrace:

```
*** API error: POST: http://127.0.0.1:7860/sdapi/v1/img2img {'error': 'AttributeError', 'detail': '', 'body': '', 'errors': "'NoneType' object has no attribute 'startswith'"}
Traceback (most recent call last):
File "C:\Users\Neilm\webui\venv\lib\site-packages\anyio\streams\memory.py", line 98, in receive
return self.receive_nowait()
File "C:\Users\Neilm\webui\venv\lib\site-packages\anyio\streams\memory.py", line 93, in receive_nowait
raise WouldBlock
anyio.WouldBlock

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\middleware\base.py", line 78, in call_next
message = await recv_stream.receive()
File "C:\Users\Neilm\webui\venv\lib\site-packages\anyio\streams\memory.py", line 118, in receive
raise EndOfStream
anyio.EndOfStream

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:\Users\Neilm\webui\modules\api\api.py", line 196, in exception_handling
return await call_next(request)
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\middleware\base.py", line 84, in call_next
raise app_exc
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\middleware\base.py", line 70, in coro
await self.app(scope, receive_or_disconnect, send_no_error)
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\middleware\base.py", line 108, in __call__
response = await self.dispatch_func(request, call_next)
File "C:\Users\Neilm\webui\modules\api\api.py", line 158, in log_and_time
res: Response = await call_next(req)
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\middleware\base.py", line 84, in call_next
raise app_exc
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\middleware\base.py", line 70, in coro
await self.app(scope, receive_or_disconnect, send_no_error)
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\middleware\cors.py", line 84, in __call__
await self.app(scope, receive, send)
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\middleware\gzip.py", line 26, in __call__
await self.app(scope, receive, send)
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\middleware\exceptions.py", line 79, in __call__
raise exc
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\middleware\exceptions.py", line 68, in __call__
await self.app(scope, receive, sender)
File "C:\Users\Neilm\webui\venv\lib\site-packages\fastapi\middleware\asyncexitstack.py", line 21, in __call__
raise e
File "C:\Users\Neilm\webui\venv\lib\site-packages\fastapi\middleware\asyncexitstack.py", line 18, in __call__
await self.app(scope, receive, send)
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\routing.py", line 718, in __call__
await route.handle(scope, receive, send)
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\routing.py", line 276, in handle
await self.app(scope, receive, send)
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\routing.py", line 66, in app
response = await func(request)
File "C:\Users\Neilm\webui\venv\lib\site-packages\fastapi\routing.py", line 237, in app
raw_response = await run_endpoint_function(
File "C:\Users\Neilm\webui\venv\lib\site-packages\fastapi\routing.py", line 165, in run_endpoint_function
return await run_in_threadpool(dependant.call, **values)
File "C:\Users\Neilm\webui\venv\lib\site-packages\starlette\concurrency.py", line 41, in run_in_threadpool
return await anyio.to_thread.run_sync(func, *args)
File "C:\Users\Neilm\webui\venv\lib\site-packages\anyio\to_thread.py", line 33, in run_sync
return await get_asynclib().run_sync_in_worker_thread(
File "C:\Users\Neilm\webui\venv\lib\site-packages\anyio\_backends\_asyncio.py", line 877, in run_sync_in_worker_thread
return await future
File "C:\Users\Neilm\webui\venv\lib\site-packages\anyio\_backends\_asyncio.py", line 807, in run
result = context.run(func, *args)
File "C:\Users\Neilm\webui\modules\api\api.py", line 611, in img2imgapi
p.init_images = [decode_base64_to_image(
File "C:\Users\Neilm\webui\modules\api\api.py", line 611, in
p.init_images = [decode_base64_to_image(
File "C:\Users\Neilm\webui\modules\api\api.py", line 80, in decode_base64_to_image
if encoding.startswith("http://") or encoding.startswith("https://"):
AttributeError: 'NoneType' object has no attribute 'startswith'
```

It might be related to this empty area for "Image" in the plugin? I can't click on it or get any init image in there, if that's what I'm supposed to do? It used to just work with a rectangular selection on the canvas.